From a technical point of view, the detection of pipeline leaks may be considered to be a technology that is still being developed because of the extremely significant limitations associated with the current commercially available technologies.
By the way, we must said that detection systems based on mass balance do not apply to pipelines transporting gases and especially to multiphase fluid transporting pipelines due to the intrinsic lack of accuracy of the physical models associated with these types of flow.
On the other hand, detection based on acoustic wave sensing fails or gives unsatisfactory results when the ends of the pipeline are connected to devices that influence acoustic propagation, or which generate signals that are similar to a leak.
This is, for example, the case when a valve is opened, where the fluid dynamic transient is similar to that of a leak, or the case of a pipeline that discharges into a buffer reservoir, which has the effect of canceling out the acoustic pressure wave.
In general terms, the technologies available nowadays are based on mechanistic models, where the operational state of the system is continuously compared to a model.
Non-mechanistic alternatives include the injection of chemical tracers, the analysis of acoustic emissions and pressure waves, visual inspection, the analysis of thermal variations associated with leaks and the emission of radio or radar waves by probes (pigs) introduced into the pipeline. In spite of their relative diffusion, these solutions are often unsatisfactory, either because of their high operational complexity, false alarms, failure to signal an alarm etc. or because of their high intrinsic costs.